package cn.tedu;

import java.util.ArrayList;
import java.util.Collection;

public class MeiRiLianXi {
    public static void main(String[] args) {
        StringBuffer a = new StringBuffer("大家好！");
        System.out.println(a.append("我是程序员！"));
        System.out.println(a.insert(6,"优秀的"));
        System.out.println(a.replace(6,9,"牛牛的"));
        System.out.println(a.delete(0,4));


    }
}
